EventID 1315 Membership credential verification failed

Looking through my logs I found at least one of those log entrys for each user trying to/actually authenticating.

The error seems to appear even if the login was successful, but I'm investigating a bunch of reports, where users where not able to login after all. Looking through my google results nothing came up, which would have helped. Checked all the fba settings,
but since I can't reproduce the failed login, the error message is everything I can stick to at the moment.

thanks for the fast reply. The option "Login Created User" is indeed activated, but I really have no clue what's causing this behavior. I've found the applicationname suggestion, but all my settings seemed to be correct in all web.config files.

In the end the user is able to login in an additional step, but I'm wondering. Since it's not working I could also disable it. I'll try to recreate the behavior with a fresh SharePoint and FBA Pack installation, but I'm starting to think, that I've caused
this problem by myself.

The only other thing I can think of to suggest is to make sure that 'Review Membership Requests' is turned off in the FBA Site Configuration. Login Created User will not work when Review Membership Requests is turned on.

I got some new informations. I found those lines of code in the uls log and what happened was that a user tried to request an account using Firefox. After entering username, emailadresse, First and Lastname and the security code, he got an unknown error
in return

This happened at the same time like the errormessage above and in the end the user was created in the server, but he hasn't been assigned to the default group. So his account exists, but it's not in SharePoint. I'm waiting for feedback if the email has been
send out, but I don't think it happened.

I haven't changed the hashing algorithm, but I'm able to recreate the error message in both event and uls log. Although I couldn't believe it in the first place, it's caused by any user entering a wrong password.

So whenever you're using aspnetdb for you fba usermanagement and an user enters a wrong password, you end up having an errormessage each in event and uls log. I could reproduce the error on an other server, where your fba pack isn't installed at all.

I'm amazed by the fact, that it seems to be always the case, that a wrong user password adds error logs. Somehow I wasn't able to find other threads concerning this problem even give the fact that everybody else should the same problem with their login.
Could you confirm this to me?